Effects of vocal nodules on acoustic characteristics of voice in children : an acoustic analysis of voice

Objective : In the present study, an attempt was made to evaluate the acoustic characteristics of voice in pediatric patients with vocal nodules using acoustic analysis of voice. Methods : Thirty-five pediatric patients with vocal nodules and 32 control children without dysphonia were enrolled in this study. Their voice samples were analyzed using the Multi-Dimensional Voice Program. Acoustic parameters of voice, such as pitch period perturbation quotient (PPQ), amplitude perturbation quotient (APQ), and noise-to-harmonic ratio (NHR), were measured. Results : In phonation at a loudness of over 80 dBA, the PPQ, APQ, and NHR values of the voice sig-nificantly increased in children with vocal nodules than in the control children without dysphonia. The sensitiv- ities and specificities of PPQ, APQ, and NHR for prediction of vocal nodules in children were 62.86% and 84.38%, 74.29% and 75.00%, and 31.43% and 93.75%, respectively. Discussion : The present findings suggest that vocal nod -ules affect vocal fold vibration, resulting in impaired control of pitch and loudness leading to increased noise components. NHR could be used to evaluate the efficacy of treatment, such as voice rehabilitation, in pediatric patients with vocal nodules because of its high specificity for prediction of vocal nodules in children.